In applications that include biomedical dosing, biochemical reaction systems, fluidic mixing, and fluidic regulation, the precise control of the flow of a fluid on a very small scale is desired. To accomplish this objective in the past, single valve systems have been provided where the valve opening is varied according to the rate of flow desired. These are not inherently linear, varying with the third power of the channel cross sectional height. In order to achieve the control required of such assemblies, complex control systems are required which can be costly compared to the fabrication costs of micro machined arrays.
The present invention provides for fluid flow regulation through an array of microvalves. Micro valves are fabricated using photolithography techniques on semiconductor material and produce extremely small dimension valves. In such a situation, it is important that the individual valves in the array have small leakage in the shut state, have a linear flow relationship to both pressure differentials over a range of pressures and over the full array from one to all valves open.
To accomplish this purpose, an array of micro valves, used for control of a fluid flow, has a substrate with a plurality of apertures for directing the fluid to flow from one side to another. A micromechanically formed fluid seal surrounds each aperture along with a valve diaphragm associated with each seal and micromechanically formed to selectively open and close the aperture by making contact with the seal. Electrical contact is made to the valve diaphragms and substrate for selective valve closure or opening. A conduit leads a fluid flow to the underside of the array and a further conduit leads it away from the array after passing through the selectively opened diaphragms.